What is acid free tissue and what is the difference between buffered and unbuffered or non buffered tissue http://allenpaperconz this. Acid-free paper is paper that if infused in water yields a neutral or basic ph (7 or slightly greater) it can be made from any cellulose fiber as long as the active. Unbuffered tissue is ideal for use in storage of textiles made of silk and wool fibers (or unknown fibers,) as well as color photographs also an excellent tissue for.